diff mbox series

[V2] Revert "PCI: tegra194: Enable support for 256 Byte payload"

Message ID 20230619014218.1970846-1-vidyas@nvidia.com (mailing list archive)
State Superseded
Delegated to: Krzysztof WilczyƄski
Headers show
Series [V2] Revert "PCI: tegra194: Enable support for 256 Byte payload" | expand

Commit Message

Vidya Sagar June 19, 2023, 1:42 a.m. UTC
This reverts commit 4fb8e46c1bc4 ("PCI: tegra194: Enable
support for 256 Byte payload").

Consider a PCIe hierarchy with a PCIe switch and a device connected
downstream of the switch that has support for MPS which is the minimum in
the hierarchy, and root port programmed with an MPS in its DevCtl register
that is greater than the minimum. In this scenario, the default bus
configuration of the kernel i.e. "PCIE_BUS_DEFAULT" doesn't configure the
MPS settings in the hierarchy correctly resulting in the device with
support for minimum MPS in the hierarchy receiving the TLPs of size more
than that. Although this can be addressed by appending "pci=pcie_bus_safe"
to the kernel command line, it doesn't seem to be a good idea to always
have this commandline argument even for the basic functionality to work.

Reverting commit 4fb8e46c1bc4 ("PCI: tegra194: Enable support for 256
Byte payload") avoids this requirement and ensures that the basic
functionality of the devices irrespective of the hierarchy and the MPS of
the devices in the hierarchy.

To reap the benefits of having support for higher MPS, optionally, one can
always append the kernel command line with "pci=pcie_bus_perf".

Fixes: 4fb8e46c1bc4 ("PCI: tegra194: Enable support for 256 Byte payload")
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V2:
* Addressed review comments from Bjorn

 drivers/pci/controller/dwc/pcie-tegra194.c | 13 -------------
 1 file changed, 13 deletions(-)

Comments

kernel test robot June 19, 2023, 3:42 a.m. UTC | #1
Hi Vidya,

kernel test robot noticed the following build errors:

[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus linus/master v6.4-rc7 next-20230616]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Vidya-Sagar/Revert-PCI-tegra194-Enable-support-for-256-Byte-payload/20230619-094403
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20230619014218.1970846-1-vidyas%40nvidia.com
patch subject: [PATCH V2] Revert "PCI: tegra194: Enable support for 256 Byte payload"
config: arm64-defconfig (https://download.01.org/0day-ci/archive/20230619/202306191113.M2RDKBvQ-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230619/202306191113.M2RDKBvQ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306191113.M2RDKBvQ-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/pci/controller/dwc/pcie-tegra194.c: In function 'tegra_pcie_dw_host_init':
>> drivers/pci/controller/dwc/pcie-tegra194.c:906:17: error: 'val_16' undeclared (first use in this function)
     906 |                 val_16 = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
         |                 ^~~~~~
   drivers/pci/controller/dwc/pcie-tegra194.c:906:17: note: each undeclared identifier is reported only once for each function it appears in
   drivers/pci/controller/dwc/pcie-tegra194.c: In function 'pex_ep_event_pex_rst_deassert':
   drivers/pci/controller/dwc/pcie-tegra194.c:1865:17: error: 'val_16' undeclared (first use in this function)
    1865 |                 val_16 = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
         |                 ^~~~~~


vim +/val_16 +906 drivers/pci/controller/dwc/pcie-tegra194.c

56e15a238d9278 Vidya Sagar   2019-08-13  867  
64451ac83fe6ab Bjorn Helgaas 2022-08-04  868  static int tegra_pcie_dw_host_init(struct dw_pcie_rp *pp)
56e15a238d9278 Vidya Sagar   2019-08-13  869  {
56e15a238d9278 Vidya Sagar   2019-08-13  870  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
f1ab409d578752 Vidya Sagar   2022-07-21  871  	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
56e15a238d9278 Vidya Sagar   2019-08-13  872  	u32 val;
56e15a238d9278 Vidya Sagar   2019-08-13  873  
275e88b06a277c Rob Herring   2020-12-18  874  	pp->bridge->ops = &tegra_pci_ops;
275e88b06a277c Rob Herring   2020-12-18  875  
369b868f4a2ef8 Vidya Sagar   2020-11-26  876  	if (!pcie->pcie_cap_base)
369b868f4a2ef8 Vidya Sagar   2020-11-26  877  		pcie->pcie_cap_base = dw_pcie_find_capability(&pcie->pci,
369b868f4a2ef8 Vidya Sagar   2020-11-26  878  							      PCI_CAP_ID_EXP);
369b868f4a2ef8 Vidya Sagar   2020-11-26  879  
56e15a238d9278 Vidya Sagar   2019-08-13  880  	val = dw_pcie_readl_dbi(pci, PCI_IO_BASE);
56e15a238d9278 Vidya Sagar   2019-08-13  881  	val &= ~(IO_BASE_IO_DECODE | IO_BASE_IO_DECODE_BIT8);
56e15a238d9278 Vidya Sagar   2019-08-13  882  	dw_pcie_writel_dbi(pci, PCI_IO_BASE, val);
56e15a238d9278 Vidya Sagar   2019-08-13  883  
56e15a238d9278 Vidya Sagar   2019-08-13  884  	val = dw_pcie_readl_dbi(pci, PCI_PREF_MEMORY_BASE);
56e15a238d9278 Vidya Sagar   2019-08-13  885  	val |= CFG_PREF_MEM_LIMIT_BASE_MEM_DECODE;
56e15a238d9278 Vidya Sagar   2019-08-13  886  	val |= CFG_PREF_MEM_LIMIT_BASE_MEM_LIMIT_DECODE;
56e15a238d9278 Vidya Sagar   2019-08-13  887  	dw_pcie_writel_dbi(pci, PCI_PREF_MEMORY_BASE, val);
56e15a238d9278 Vidya Sagar   2019-08-13  888  
56e15a238d9278 Vidya Sagar   2019-08-13  889  	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0);
56e15a238d9278 Vidya Sagar   2019-08-13  890  
56e15a238d9278 Vidya Sagar   2019-08-13  891  	/* Enable as 0xFFFF0001 response for CRS */
56e15a238d9278 Vidya Sagar   2019-08-13  892  	val = dw_pcie_readl_dbi(pci, PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT);
56e15a238d9278 Vidya Sagar   2019-08-13  893  	val &= ~(AMBA_ERROR_RESPONSE_CRS_MASK << AMBA_ERROR_RESPONSE_CRS_SHIFT);
56e15a238d9278 Vidya Sagar   2019-08-13  894  	val |= (AMBA_ERROR_RESPONSE_CRS_OKAY_FFFF0001 <<
56e15a238d9278 Vidya Sagar   2019-08-13  895  		AMBA_ERROR_RESPONSE_CRS_SHIFT);
56e15a238d9278 Vidya Sagar   2019-08-13  896  	dw_pcie_writel_dbi(pci, PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT, val);
56e15a238d9278 Vidya Sagar   2019-08-13  897  
56e15a238d9278 Vidya Sagar   2019-08-13  898  	/* Configure Max lane width from DT */
56e15a238d9278 Vidya Sagar   2019-08-13  899  	val = dw_pcie_readl_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKCAP);
56e15a238d9278 Vidya Sagar   2019-08-13  900  	val &= ~PCI_EXP_LNKCAP_MLW;
56e15a238d9278 Vidya Sagar   2019-08-13  901  	val |= (pcie->num_lanes << PCI_EXP_LNKSTA_NLW_SHIFT);
56e15a238d9278 Vidya Sagar   2019-08-13  902  	dw_pcie_writel_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKCAP, val);
56e15a238d9278 Vidya Sagar   2019-08-13  903  
a54e190737181c Vidya Sagar   2022-07-21  904  	/* Clear Slot Clock Configuration bit if SRNS configuration */
a54e190737181c Vidya Sagar   2022-07-21  905  	if (pcie->enable_srns) {
a54e190737181c Vidya Sagar   2022-07-21 @906  		val_16 = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
a54e190737181c Vidya Sagar   2022-07-21  907  					   PCI_EXP_LNKSTA);
a54e190737181c Vidya Sagar   2022-07-21  908  		val_16 &= ~PCI_EXP_LNKSTA_SLC;
a54e190737181c Vidya Sagar   2022-07-21  909  		dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA,
a54e190737181c Vidya Sagar   2022-07-21  910  				   val_16);
a54e190737181c Vidya Sagar   2022-07-21  911  	}
a54e190737181c Vidya Sagar   2022-07-21  912  
56e15a238d9278 Vidya Sagar   2019-08-13  913  	config_gen3_gen4_eq_presets(pcie);
56e15a238d9278 Vidya Sagar   2019-08-13  914  
56e15a238d9278 Vidya Sagar   2019-08-13  915  	init_host_aspm(pcie);
56e15a238d9278 Vidya Sagar   2019-08-13  916  
6b6fafc1abc7c0 Vidya Sagar   2020-12-03  917  	/* Disable ASPM-L1SS advertisement if there is no CLKREQ routing */
6b6fafc1abc7c0 Vidya Sagar   2020-12-03  918  	if (!pcie->supports_clkreq) {
6b6fafc1abc7c0 Vidya Sagar   2020-12-03  919  		disable_aspm_l11(pcie);
6b6fafc1abc7c0 Vidya Sagar   2020-12-03  920  		disable_aspm_l12(pcie);
6b6fafc1abc7c0 Vidya Sagar   2020-12-03  921  	}
6b6fafc1abc7c0 Vidya Sagar   2020-12-03  922  
a54e190737181c Vidya Sagar   2022-07-21  923  	if (!pcie->of_data->has_l1ss_exit_fix) {
56e15a238d9278 Vidya Sagar   2019-08-13  924  		val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
56e15a238d9278 Vidya Sagar   2019-08-13  925  		val &= ~GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL;
56e15a238d9278 Vidya Sagar   2019-08-13  926  		dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val);
a54e190737181c Vidya Sagar   2022-07-21  927  	}
56e15a238d9278 Vidya Sagar   2019-08-13  928  
56e15a238d9278 Vidya Sagar   2019-08-13  929  	if (pcie->update_fc_fixup) {
56e15a238d9278 Vidya Sagar   2019-08-13  930  		val = dw_pcie_readl_dbi(pci, CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF);
56e15a238d9278 Vidya Sagar   2019-08-13  931  		val |= 0x1 << CFG_TIMER_CTRL_ACK_NAK_SHIFT;
56e15a238d9278 Vidya Sagar   2019-08-13  932  		dw_pcie_writel_dbi(pci, CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF, val);
56e15a238d9278 Vidya Sagar   2019-08-13  933  	}
56e15a238d9278 Vidya Sagar   2019-08-13  934  
56e15a238d9278 Vidya Sagar   2019-08-13  935  	clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ);
56e15a238d9278 Vidya Sagar   2019-08-13  936  
275e88b06a277c Rob Herring   2020-12-18  937  	return 0;
275e88b06a277c Rob Herring   2020-12-18  938  }
275e88b06a277c Rob Herring   2020-12-18  939
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 4fdadc7b045f..877d81b13334 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -892,7 +892,6 @@  static int tegra_pcie_dw_host_init(struct dw_pcie_rp *pp)
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
 	u32 val;
-	u16 val_16;
 
 	pp->bridge->ops = &tegra_pci_ops;
 
@@ -900,11 +899,6 @@  static int tegra_pcie_dw_host_init(struct dw_pcie_rp *pp)
 		pcie->pcie_cap_base = dw_pcie_find_capability(&pcie->pci,
 							      PCI_CAP_ID_EXP);
 
-	val_16 = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL);
-	val_16 &= ~PCI_EXP_DEVCTL_PAYLOAD;
-	val_16 |= PCI_EXP_DEVCTL_PAYLOAD_256B;
-	dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL, val_16);
-
 	val = dw_pcie_readl_dbi(pci, PCI_IO_BASE);
 	val &= ~(IO_BASE_IO_DECODE | IO_BASE_IO_DECODE_BIT8);
 	dw_pcie_writel_dbi(pci, PCI_IO_BASE, val);
@@ -1756,7 +1750,6 @@  static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	struct device *dev = pcie->dev;
 	u32 val;
 	int ret;
-	u16 val_16;
 
 	if (pcie->ep_state == EP_STATE_ENABLED)
 		return;
@@ -1887,11 +1880,6 @@  static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	pcie->pcie_cap_base = dw_pcie_find_capability(&pcie->pci,
 						      PCI_CAP_ID_EXP);
 
-	val_16 = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL);
-	val_16 &= ~PCI_EXP_DEVCTL_PAYLOAD;
-	val_16 |= PCI_EXP_DEVCTL_PAYLOAD_256B;
-	dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL, val_16);
-
 	/* Clear Slot Clock Configuration bit if SRNS configuration */
 	if (pcie->enable_srns) {
 		val_16 = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
@@ -1900,7 +1888,6 @@  static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 		dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA,
 				   val_16);
 	}
-
 	clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ);
 
 	val = (ep->msi_mem_phys & MSIX_ADDR_MATCH_LOW_OFF_MASK);